The correct answer is High melting and boiling points.

Key Points

• When two non-metals react with each other, they form a covalent compound.
• Covalent compounds have low melting and boiling points.

Additional Information

• Covalent compounds generally do not conduct electricity. They possess low enthalpies of vaporization and fusion, with bond energies typically around 80 kcal per mole, characterized by strong localized bonds between atoms.
• Water is a polar solvent, whereas most covalent compounds are non-polar.
• This means that covalent compounds do not dissolve well in water and often form a separate layer on the surface of the water.
• Therefore, we can say that covalent compounds are generally insoluble in water.
• A covalent bond is a chemical bond that involves the sharing of electron pairs between atoms.
• These electron pairs are known as shared pairs or bonding pairs. The stable balance of attractive and repulsive forces between atoms when they share electrons is what defines a covalent bond.